Effects of magnetic and non-magnetic doping on the vortex lattice in MgB$_2$
| Autor: | Louden, E. R., Manni, S., Van Zandt, J. E., Leishman, A. W. D., Taufour, V., Bud'ko, S. L., DeBeer-Schmitt, L., Honecker, D., Dewhurst, C. D., Canfield, P. C., Eskildsen, M. R. |
|---|---|
| Rok vydání: | 2022 |
| Předmět: | |
| Zdroj: | J. Appl. Cryst. 55, 693 (2022) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1107/S160057672200468X |
| Popis: | Using small-angle neutron scattering we have studied the vortex lattice in superconducting MgB$_2$ with the magnetic field applied along the $c$-axis, doped with either manganese or carbon to achieve a similar suppression of the critical temperature. For Mn-doping, the vortex lattice phase diagram remains qualitatively similar to that of pure MgB$_2$, undergoing a field-and temperature-driven $30^{\circ}$ rotation transition, indicating only a modest effect on the vortex-vortex interaction. In contrast, the vortex lattice rotation transition is completely suppressed in the C-doped case, likely due to a change in the electronic structure which affects the two-band/two-gap nature of superconductivity in MgB2. The vortex lattice longitudinal correlation length shows the opposite behavior, remaining roughly unchanged between pure and C-doped MgB$_2$ while it is significantly reduced in the Mn-doped case. However, the extensive vortex lattice metastability and related activated behavior, observed in conjunction with the vortex lattice transition in pure MgB$_2$, is also seen in the Mn doped sample. This shows that the vortex lattice disordering is not associated with a substantially increased vortex pinning. Comment: To appear in the Journal of Applied Crystallography for the special issue "Magnetic Small-Angle Neutron Scattering - from nanoscale magnetism to long-range magnetic structures" |
| Databáze: | arXiv |
| Externí odkaz: |
|